JP4723454B2 - Method and apparatus for controlling triggering of oxygen scavenging composition using a wrapping shade - Google Patents

Abstract

An apparatus is provided for activating an oxygen scavenging composition that includes a plurality of UV lamps arranged in a bank and disposed in a UV chamber; the UV lamps include first and second sides through which UV light is transmittable. A series of guide rolls disposed in the UV chamber define a film pathway for directing a film in close proximity with the first and second sides of the UV lamps. The UV shade is arranged to wrap about the first and second sides of the UV lamps, and may be configured to move between an open, partially open, and closed position so that the dosage of UV light to which the film is exposed may be controlled by adjusting the degree to which the shade is open. As a result, the UV shade may limit UV exposure without having to turn off the UV lamps.

Description

  The present invention relates generally to articles used for packaging oxygen sensitive materials, and more specifically to triggering an oxygen scavenging composition.

  By reducing the exposure of oxygen sensitive articles to oxygen, the quality and shelf life of the articles are maintained and improved. For example, by reducing oxygen exposure of oxygen sensitive food products in a packaging system, the quality of the food product is maintained and food spoilage is avoided. By reducing oxygen exposure, products are kept longer in inventory, thereby reducing costs incurred by having to be disposed and replenished.

  One way to reduce oxygen exposure is to incorporate an oxygen scavenger (scavenger) into the packaging structure. An oxygen scavenging composition is a composition that consumes, depletes or reduces the amount of oxygen in a given environment. There are a variety of different compositions that can be used in oxygen scavenging applications. Exemplary compositions are described in US Pat. No. 5,211,875 to Speer et al., US Pat. No. 5,350,622, US Pat. No. 5,399,289, and US Pat. No. 5,811,027, and WO 99/48963 to Cai et al. And are fully incorporated by reference. The oxygen scavenging composition can include a substituted or unsubstituted ethylenically unsaturated composition that can scavenge oxygen upon activation or triggering. The oxygen scavenging composition can also include a metal catalyst and a photoinitiator to assist in the activation of oxygen scavenging, and the composition can provide sufficient power in an amount of time sufficient to initiate oxygen scavenging, such as actinic radiation Can be “triggered” by exposure to a radiation source having High temperatures can also assist in triggering the oxygen scavenging composition.

Methods for triggering the oxygen scavenging composition typically use a low pressure mercury germicidal lamp with an intensity output of about 5 mW / cm ² to 10 mW / cm ² . These lamps are commonly referred to as sterilization because the main emission is at 254 nm. During UV light exposure, the composition can also be heated to further improve the trigger. Heating the composition makes it possible to trigger the oxygen scavenging composition with a lower UV dose. Instrument systems and methods for triggering oxygen scavenging membranes and articles are described in U.S. Pat. No. 6,287,481 to Luthra et al., U.S. Pat. No. 6,449,923 to Cook et al., U.S. Pat. No. 6,233,907 to Cook et al., And Becraft et al. U.S. Pat. No. 5,911,910 to U.S. Pat. No. 5,911,910, and copending U.S. patent application Ser. No. 11/007821, filed Dec. 8, 2004, all of which are fully incorporated herein. Built in.
US Pat. No. 5,211,875 US Pat. No. 5,350,622 US Pat. No. 5,399,289 US Pat. No. 5,811,027 WO99 / 48963 pamphlet US Pat. No. 6,287,481 US Pat. No. 6,449,923 US Pat. No. 6,233,907 US Pat. No. 5,911,910 Co-pending US patent application Ser. No. 11/007821 US Pat. No. 6,942,821 US Pat. No. 5,498,364 International Publication No. 95/04776 Pamphlet International Publication No. 95/02616 Pamphlet US Pat. No. 5,958,254 US Pat. No. 5,859,145 US Pat. No. 6,255,248 US Pat. No. 6,214,254 US patent application Ser. No. 10 / 746,626 International Publication No. 02/18489 Pamphlet US Pat. No. 6,599,598

  In some situations, it may be desirable for the oxygen scavenging composition to limit or prevent further exposure to or exposure to UV light. Current methods and equipment may rely on turning off the lights to prevent or limit UV exposure. However, many germicidal lamps can be sensitive to being turned on and off. In some cases, increasing the on / off cycle can significantly shorten the life of the lamp. Thus, there is a need to limit the amount of light that can be exposed to an oxygen scavenging composition that helps reduce the need to turn on and off the UV lamp.

  The present invention provides an apparatus and method for activating an oxygen scavenging composition that can help control the amount of UV light that the oxygen scavenging composition can be exposed to. In one embodiment, the present invention provides an apparatus for activating a film having an oxygen scavenging composition comprising a UV shade that can be at least partially disposed between the film and one or more UV lamps. Can be targeted. The UV shade can include a UV opaque material that can substantially prevent UV light from contacting the film. As a result, a UV shade can be used to limit UV light exposure without the need to turn off the UV lamp.

  In one embodiment, the apparatus can comprise a plurality of UV lamps configured in a bank and disposed in a UV chamber, the bank of UV lamps comprising a first side through which UV light can be transmitted and a second side. Including side. The apparatus can also include a series of guide rolls disposed in the UV chamber that define a film path for directing the film in close proximity to the first and second sides of the bank of UV lamps. The apparatus can also include a retractable and extensible UV shade constructed and arranged to wrap around the first and second sides of the UV lamp. In one embodiment, the UV shade has an open position, a partially open position, such that by adjusting the degree to which the shade is open, the dose of UV light to which the film is exposed can be controlled. And can be configured to move between closed positions.

  In other embodiments, the apparatus can also include a shade drive mechanism that can move the UV shade between different degrees of openness. In one embodiment, the shade drive mechanism includes at least one endless belt that is attached to the edge of the UV shade and that shades around the first side and the second side of the UV lamp. Wrapping and thereby operable to control the amount of UV light that can contact the membrane. In yet another embodiment, the UV shade is in a path that is substantially parallel to the film path around the first and second sides of the UV lamp and at a speed at which the film is traveling through the UV chamber. It can be configured to move between an open position and a closed position at a rate of near speed. As a result, the UV shade can be used to prevent UV light from contacting the inert film, while at the same time allowing the oxygen scavenging composition to continue to be activated in the activated process. . In one embodiment, the UV shade can be moved to the closed position when almost all of the active film has exited the UV chamber. The apparatus can also include a driven roll configured to drive the film through the UV chamber. The UV dose to which the film is exposed can also be controlled by controlling the rate at which the film travels through the UV chamber.

  In one embodiment, the device is included in a system for activating an oxygen scavenging composition. The system can include an inventory section that can pick up any active film placed in the UV chamber. In some embodiments, the inventory system can be used in conjunction with UV shades and driven rolls to limit the amount of light that the oxygen scavenging composition can be exposed to. In one embodiment, the UV shade can be moved to a closed position in response to a predetermined event, such as stopping the advancement of the membrane. In other embodiments, the predetermined event may be an outage of the packaging operation that may occur downstream of the UV chamber.

  In response to a stop or other event, the UV shade can be moved to the closed position at a rate close to the rate at which the film travels through the UV chamber. When the shade is moved to the closed position, the inert film entering the UV chamber is prevented from being exposed to UV light. When traveling through the UV chamber, the film already in the UV chamber and in the process to be activated is not shielded by the UV shade and can be activated before exiting the UV chamber. It can be exposed to light. The UV shade can be placed in the closed position when almost all of the active film has exited the UV chamber. The progressive movement of the membrane can be stopped at this point. In some embodiments, the active film exiting the UV chamber can be temporarily stored in an inventory system.

  In yet other embodiments, the system and apparatus can include a control unit, such as a programmable logic controller, that can be operatively connected to the UV shade and the driven roll. In other embodiments, the control unit may be configured to control the operation of the inventory system. The control unit, in one embodiment, controls the amount of UV light that can come into contact with the composition and controls the rate at which the web travels through the UV chamber so that the oxygen scavenging composition is It may be possible to control the amount of UV radiation that can be exposed.

  Thus, the present invention allows the oxygen scavenging composition to be exposed and substantially prevents UV light from coming into contact with the oxygen scavenging composition without requiring the UV lamp to be turned off. An apparatus and a method for controlling the amount of UV irradiation that can be used for the present invention.

  Although the present invention has been generally described above, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale.

  The invention is described more fully hereinafter with reference to the accompanying drawings, some of which are shown, but not all of the embodiments of the invention. Indeed, the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout the drawings.

  Referring to FIG. 1, a system for activating an oxygen scavenging composition is shown and designated generally by reference numeral 10. As shown in FIG. 1, the system can include a UV chamber 12 for activating the oxygen scavenging composition. The UV chamber includes a UV light source 14 that emits UV light having a power sufficient to activate the oxygen scavenging composition. In some embodiments, the oxygen scavenging composition can be disposed on a flexible material such as a membrane that travels through the UV chamber and activates the oxygen scavenging composition. Is exposed to a sufficiently strong UV light source for a sufficient dwell time. As used herein, the term “film” refers to a variety of different things that can be used in connection with a UV chamber, including but not limited to laminates, webs, sheets, coatings, etc. on a substrate or carrier. It should be understood to refer to a flexible material. In one embodiment, the present invention may be particularly useful for activating oxygen scavenging compositions that can be used to package articles. Examples include membranes that can be used as components in rigid, semi-rigid, or flexible products, membranes that can be used as coupons or inserts in packages, over oxygen barrier membranes, in oxygen barrier membranes, Alternatively, a film that can be included as a part of the oxygen barrier film or a film having a relatively high oxygen transmission rate is included.

  In one embodiment, the system may include an inventory section 16 for temporarily accumulating active membranes and a packaging system 18 for packaging products or storage. In some embodiments, a membrane having an inert oxygen scavenging composition can be provided from a continuous roll of membrane 20. In one embodiment, the film 22 can be exposed to a sufficiently strong UV light source for a dwell time sufficient to enter the UV chamber 12 and activate the oxygen scavenging composition. The system of the present invention is a packaging system 18 in which the membrane is activated as described herein and then the active membrane is used to package an article such as an oxygen sensitive product. Note that it can be used in a packaging environment, such as in a facility where both proceeding to Alternatively, the system can be used at the membrane manufacturing location or at a location where the membrane is processed as described herein and then transported to a location where the membrane is stored and the packaging of the article is performed. It can be used to activate the membrane as described in the specification. Thus, the system and method of the present invention can be implemented independently of the packaging operation. Multiple steps can be taken to substantially retain the oxygen scavenging function of the active film until the active film is used for packaging applications. One way to do this is disclosed in US Pat. No. 6,942,821 to Dayrit et al., Fully incorporated herein by reference.

  The UV chamber 12, also referred to as the trigger chamber, can include one or more UV lamps 24 disposed in the interior space 26 of the UV chamber. In one embodiment, the UV lamps can be placed in a lamp bank 28 in which the UV lamps can be spaced apart and substantially parallel to each other. In other embodiments, the UV lamp can be configured in other orientations, such as a non-linear configuration. In some embodiments, the UV chamber can include more than one UV lamp bank. In some embodiments, the UV lamp bank can include a plurality of UV lamps, the plurality of UV lamps being substantially parallel to each other and arranged side by side to allow optimal exposure to the film. Can be done. The lamp bank of some embodiments can have about 5 to 20 UV lamps. The lamp bank can have a wide range of structures and configurations. The distance between the film and the UV lamp can be about 1 cm to 8 cm, such as about 4 cm.

Lamps useful in the present invention are typically about 10 mW / cm ² to 35 mW measured at a distance of about 2 inches from the lamp surface and an air temperature of about 71 ° C. (about 160 ° F.). It has an output intensity at 254 nm which is / cm ² . A suitable value for the output intensity is about 15 mW / cm ² to 35 mW / cm ² . It has been found that UV-C light, such as UV light of bactericidal wavelength, is effective in triggering certain oxygen scavenging compositions. Useful wavelengths are, for example, between 200 nm and 280 nm, such as 254 nm. In some embodiments, the UV lamp may comprise a mercury amalgam lamp. A low pressure mercury amalgam lamp is a germicidal lamp that produces the highest output at wavelengths between 200 nm and 280 nm. Within this region, the lamp can generate intensities in excess of 20 mW / cm ² . Typically, mercury amalgam lamps can have an intensity at 254 nm that is about 15 mW / cm ² to 35 mW / cm ² .

  As shown in FIG. 1, the trigger chamber 12 can include an inlet 30 and an outlet 32 that define openings or slits in the chamber through which the membrane can enter or exit the chamber. The membrane can be driven to advance through the chamber 12 by a driven roll 34 or any other suitable means for advancing the membrane. The speed of the driven roll can also be adjusted to help control the UV dose to which the film is exposed. The driven roll can be selected from a wide range of rolls that can be used to drive the film in the desired direction, such as a nip roll. The driven roll can be moved with a motor device, such as an electric motor or a pneumatic motor. In the embodiment shown in FIG. 1, the trigger chamber includes a driven roll disposed adjacent to the outlet 32. The driven roll can alternatively be placed in a chamber adjacent to the inlet or outlet. The exact placement of the driven roll 34 is not critical to the practice of the present invention, and the roll maintains the forward movement of the membrane at the rate of the desired level of tension and desired speed. If possible, it should be understood that it can be placed in other locations indoors or outdoors. In some embodiments, the trigger chamber can include more than one driven roll. In one embodiment, the UV chamber can be used to drive a film from the chamber to the outside, and a first driven roll that drives the film to advance into the UV chamber. Of driven rolls. In embodiments having more than one driven roll, the speed of the driven roll can be adjusted to increase or decrease the membrane tension. Alternatively, in an embodiment of the system of the present invention that supplies the active film to the downstream packaging system, means for advancing the active film in the packaging system is used to pass through the chamber containing the UV shade system and then the outdoor And an inert film can be drawn into the packaging system.

  In one embodiment, the driven roll 34 can also assist in maintaining the film at a desired level of tension. Maintaining the membrane at the desired level of tension in the trigger chamber helps to reduce or eliminate membrane curl or wrinkles that may occur at higher temperatures. The membrane should be maintained at a certain tension, which is sufficient to maintain control of the membrane and overcome the tendency of the membrane to curl or wrinkle at higher temperatures. In some embodiments, the chamber web or membrane tension is maintained from about 0 kg to about 1.1 kg (about 0 to 2.5 pounds) per linear inch of membrane width (PLI). Some more generally, the tension is slightly greater than 0 PLI and less than 2.5 PLI, such as 0.25 PLI to 1.0 PLI. Excess tension can cause the membrane to become elongated, accompanied by a reduction in membrane width.

The trigger chamber can include a series of guide rolls 36 that guide the membrane 22 in close proximity to the UV lamp 24. Upon entering the chamber, the membrane path can be directed and defined by a guide roll. In some embodiments, the UV lamp can be configured in the chamber to include a first side 39 and a second side 41 through which the film can be directed. In this regard, FIG. 1 shows a plurality of guide rolls that define a film path in close proximity to the first and second sides of the UV lamp. In one embodiment, the membrane can be directed along the membrane path in close proximity to the first side of the UV lamp, and then wrap the second side from the first side of the UV lamp. The guide roll 36 can direct the film very close to the UV lamp. The film progression in close proximity to the first and second sides of the UV lamp can be used to activate the oxygen scavenging composition. In this embodiment, the distance between the membrane and the first side of the UV lamp can be the same as or different from the distance between the membrane and the second side of the UV lamp.

  In one embodiment, the trigger chamber can also include a dose management system that can control the UV dose to which the film can be exposed. In one embodiment, the dose management system can include a UV shade 38 that can be positioned between the membrane path and the UV lamp. In some embodiments, the UV shade may be movable between an open position, a partially open position, and a closed position. As a result, the amount of UV radiation that the film can be exposed to can be controlled by adjusting the degree to which the shade is open.

  As will be discussed in more detail below, the trigger chamber may include a shade drive system operable to move the UV shade between an open position, a partially open position, and a closed position. The shade drive system can include a shade roll 40 from which the UV shade can be extended and / or retracted. In one embodiment, the UV shade may include a leading edge 42 attached to at least one endless belt 44 that wraps around the first side and the second side of the UV lamp. The endless belt can be in mechanical communication with a motor (see briefly reference 50 in FIG. 2) operable to drive the endless belt around the UV lamp. In one embodiment, the UV shade is stretched out of or pulled into the shade roll 40 by driving an endless belt around the UV lamp. In other embodiments, the endless belt can be used to wrap the UV shade from the first side to the second side of the UV lamp.

  In one embodiment, UV light can be substantially prevented from contacting the film by moving the UV shade to the closed position. By “closed position” is meant a position where the UV shade 38 is extended to the outside of the shade roll 40 to the extent that UV light from the UV lamp 24 is prevented from reaching the film 22. Preventing UV light from contacting the film can help prevent the inactive film from being activated. In some embodiments, the UV shade is used to activate an inert film that is placed in the UV chamber or in the process of entering the UV trigger chamber without the need to turn off the UV lamp. Can be prevented. As discussed above, some UV lamps can be adversely affected by being turned off and turned on. Current methods and equipment may rely on turning the lamp off to prevent overexposure of the membrane. However, increasing the on / off cycle can significantly shorten the life of the lamp. It is therefore desirable to have a dose management system that does not require an additional on / off cycle of the lamp. Furthermore, closing the UV shade may allow the film to travel through the trigger chamber without UV exposure. Thus, UV exposure can be eliminated or substantially prevented without requiring the lamp to be turned off. This can be particularly useful when using mercury amalgam lamps. Typically, amalgam lamps have a longer warm-up time from a cold start than standard lights and can be more adversely affected by on / off cycles than standard germicidal lamps.

  As described above, the UV shade can move from a relatively open position to a closed position and vice versa. As a result, the UV shade can change position (the extent of extension from the shade roll 40) so that the amount of UV exposure received by the film can be changed. This feature is particularly useful for activating oxygen scavenging membranes over a range of packaging rates, including conditions where the packaging rate can vary normally or can be somewhat intermittent. For example, it may be common for an operator to start the packaging line at a low speed until all parameters operate properly and then rise to a higher speed. Under these conditions, a constant UV dose and consistent oxygen collection can be maintained in the trigger chamber. In addition, the trigger chamber can activate a variety of membranes with different oxygen scavenging compositions, or a given membrane intended for different end use applications. For example, if a lower collection rate is desired, the UV shade can be repositioned to reduce the amount of UV light that contacts the film. If a faster collection rate is desired, the UV shade can be repositioned to allow a greater amount of UV light to contact the film. Thus, the dose management system can also be used to control the UV exposure received by the film.

  In one embodiment, the UV shade can be capable of being at least partially disposed between the UV lamp and the membrane. In this regard, FIG. 2 shows an embodiment in which a UV lamp shade is depicted partially disposed between a plurality of UV lamps and a film having an oxygen scavenging composition. As discussed above, the trigger unit may include a UV dose management system comprising a UV shade that is in mechanical communication with a shade drive system operable to move the UV shade between different degrees of openness. it can. As shown, the shade drive system can include two endless belts 44 to which the leading edge 42 of the UV shade 38 can be attached. In one embodiment, the motor 50 can be in mechanical communication with the drive shaft 52, which can include a pair of pulleys that drive the endless belt 44 around the plurality of UV lamps 24. . In some embodiments, the idler roll 54 can be rotationally disposed about the drive shaft 52. In one embodiment, the idler roll 54 provides a surface through which the UV shade can travel as it wraps around multiple UV lamps and moves between open and closed positions. . By rotation of the drive shaft 52, the endless belt 44 can be rotated around the first side surface and the second side surface of the plurality of UV lamps. The rotation of the endless belt 44 causes the UV shade to extend or retract from the UV shade roll 40. In some embodiments, the UV shade may be under spring tension so that when released, the UV shade is automatically retracted, thereby opening the shade and exposing the UV lamp. It can be placed on the roll 40. The UV shade roll 40 can include a winding mechanism and can also include a winding shaft (not shown) that can be connected to the roll 40. The winding shaft can be actuated to wind the UV shade around the roll and thereby open the shade. The winding mechanism and winding shaft can be adjusted manually or automatically to provide the desired level of UV exposure.

  In other embodiments, the UV shade moves around the first and second sides of the plurality of UV lamps along a path substantially parallel to the path of the film as the film travels through the trigger chamber. Can be wrapped. In one embodiment, the direction in which the UV shade moves from the open position to the closed position can be approximately the same as the film direction as the film travels in close proximity to the plurality of UV lamps. In this regard, FIG. 2 shows an embodiment where the path of the UV shade is substantially parallel to the path of the film as the film travels in close proximity to the plurality of UV lamps. FIG. 2 also shows a UV shade that moves from an open position to a closed position in a direction that is substantially the same as the direction of the film as it travels in close proximity to a plurality of UV lamps. As discussed in more detail below, the dose management system can be programmed to provide the film with consistent UV irradiation over a wide range of packaging speeds, and the lamp can be turned on to prevent overexposure. It can also be used in connection with a control unit, which can eliminate the need to switch off.

  In one embodiment, the plurality of UV lamps can comprise a lamp bank in the form of a sealed cassette having a pair of double windows through which UV light can be transmitted. In this regard, FIGS. 3 and 4 show an embodiment in which a plurality of UV lamps are arranged in a cassette. As shown in FIG. 3, the UV cassette 60 can include a cassette housing 62 having a plurality of UV lamps disposed therein. The cassette housing can include a first panel 64 and a second panel 66 that together form a sealed space in which the UV lamp is placed. Typically, both panels 64, 66 have openings or windows 68 that are transparent to UV light. The opening 68 can be covered with a thin pane 70 through which UV light can be transmitted. In some embodiments, the window pane can serve several functions. In one embodiment, the window pane can seal the UV lamp so that if the UV lamp breaks, the generation of contamination is limited, i.e., the ground quartz is prevented from contacting the membrane. . The window pane can also enclose the cassette so that a controlled airflow can be introduced over the surface of the UV lamp in the air circulation system. Window pane 70 may comprise a UV transmissive material such as quartz or a thin sheet of a fluorocarbon polymer such as FEP-Teflon®. In one embodiment, the window pane 70 may be about 0.025 mm to about 0.18 mm (about 1 mil to 7 mils) thick. In other embodiments, the UV lamp can include an outer sleeve (not shown) that can protect the membrane from debris if the lamp breaks. The sleeve can be a shrinkable member or coating that can be applied to the lamp. One type of sleeve comprises FEP-Teflon® that can be heat shrunk around the lamp.

  The UV shade can be constructed of a variety of materials that are UV opaque and substantially prevent UV light from being transmitted through the aperture 68 from the UV lamp. The UV shade of some embodiments can be constructed of a thin flexible material such as a foil. Suitable materials include, but are not limited to, stainless steel, aluminum, metal alloys, UV-impermeable plastic films, metal-coated plastic films, KAPTON® polyimide films, Teflon® impregnated glass cloth, etc. Is not to be done.

  In FIG. 4, the outer panel of the cassette housing has been removed. As shown, the UV lamp 24 can include a lamp bank 28, the UV lamps being arranged in a row and being substantially parallel to each other. In some embodiments, the opposing edges 72, 74 of the cassette housing 62 can include an inlet 76 and an outlet 78 through which air can be introduced across the surface of the UV lamp. UV lamps can generate heat at temperatures in excess of about 49 ° C. (about 120 ° F.). In some embodiments, the trigger chamber can include an air circulation system that assists in maintaining the UV lamp at a desired temperature. In this regard, FIG. 4 shows conditioned air entering the cassette housing via inlet 76 and exiting the cassette via outlet 78. In some embodiments, the air exiting the cassette can be recirculated through the heat exchange and blower. In other embodiments, air exiting the cassette can be released into the trigger chamber. The lamp air circulation system can include a fan or blower, a heat exchanger, and a plenum. The heated air can be removed from the trigger chamber by a fan and directed to the heat exchanger. In the heat exchanger, the air is conditioned, such as cooled or heated, and then directed to the plenum, where it is then directed to contact the UV lamp 24 via the inlet 76. The arrows represent the air flow through the cassette housing.

  The trigger chamber can also include another air handling system to maintain the membrane at the desired temperature. Many UV lamps produce both UV-C light and heat. Infrared energy from the lamp can be used to heat the film to a temperature that can range from about 38 ° C. to about 72 ° C. (about 100 ° F. to 160 ° F.). In some embodiments, the membrane may be heated to a temperature greater than about 49 ° C. (120 ° F.). In one embodiment, the membrane may be heated to a temperature of about 60 ° C. to about 72 ° C. (about 140 ° F. to 160 ° F.). An air circulation system can be used to help prevent the membrane from exceeding the desired temperature. The air circulation system can also be used to heat the membrane to the desired temperature. In this regard, FIGS. 5 and 6 show an air handling system 80 that can be used to control the temperature of the membrane. FIG. 5 is a perspective view showing an air handling system configured to remove heated air from the trigger chamber or introduce heated air into the trigger chamber and introduce conditioned air across the membrane. FIG. 6 is a cross-sectional side view showing conditioned air introduced across the membrane path and removed from the trigger chamber. In some embodiments, the air handling system can comprise an air circulation system that can be used to maintain the membrane and lamp at a desired temperature. The air circulation system 80 can include an air intake 82, a heat exchanger (not shown), a fan or blower (not shown), and a plenum 86. A fan or blower draws heated air out of the trigger chamber. The heated air is drawn into the intake 82 and then passes through the heat exchanger. A heat exchanger can be used to condition the air. The air is then directed by the fan via a plenum 86 that directs the conditioned air at this stage to contact the membrane 22. As a result, the temperature of the film 22 can be maintained at a desired temperature so that the trigger is improved without damaging or curling the film. The chamber can be operated with slightly negative pressure. Although not shown, a vent can be placed in the air circulation system 80 that can be used to vent some portion of the air out of the room. The trigger chamber can also include an optional infrared heater (not shown) to heat the film before it enters the UV chamber.

  In some embodiments, the trigger chamber can be operatively connected to a control unit, such as a programmable logic controller. The control unit can be used to operatively control film tension, film speed, UV dose, temperature, etc. Typically, the control unit can be in communication with a driven roll (see briefly reference 34 in FIG. 1) and a shade drive system. The control unit controls the amount of UV radiation that the film can be exposed to by controlling the rate at which the film travels through the trigger chamber and / or the amount of UV light that can contact the film. can do. The control unit can also be operatively connected to one or more air circulation systems and various sensors located within the trigger system. The control unit can be used to monitor and control the film speed and UV dose. The control unit can be programmed or automated to maintain a desired level of UV exposure to which the film can be exposed. In one embodiment, the control unit can be configured to move the UV shade to a substantially closed position in response to a predetermined event, such as stopping the forward movement of the film progression.

  Returning again to FIG. 1, the trigger system 10 can also include a membrane inventory system that can be used to temporarily store membranes contained in the trigger chamber. In one embodiment, the active membrane 22 exiting the trigger chamber 12 can travel through the inventory section 16 before proceeding to the packaging system or take-up roll. The capacity of the inventory section can be expanded so that if the production line goes down, the inventory section can temporarily store any active membranes contained within the trigger chamber. After passing through the inventory section, the membrane can proceed to a packaging device or take-up roll where it can be stored for later use. In some embodiments, the volume of the inventory section can be as high as or more than the membrane volume inside the trigger chamber. The inventory section 16 can include a movable inventory shuttle 82 that can be moved to various locations so that the inventory section temporarily removes any excess membrane that may be present in the trigger chamber. Can be expanded to store. The inventory shuttle 82 can be repositioned to expand or decrease the capacity of the inventory section. In the case of a line stop, such as a stop or delay that occurs in the packaging system, the inventory shuttle can be repositioned to pick up any membrane that is placed in the trigger chamber. As a result, film UV exposure can be stopped without requiring the UV lamp to be turned off. In one embodiment, the inventory section can pick up and store the active film placed in the UV chamber.

  After the active membrane 22 exits the trigger chamber, it can be sent to a winding roll or other suitable storage means for later use, or sent to the packaging system 18 for immediate use. Can do.

  In some embodiments, the UV shade and driven roll can act in concert to control and limit the amount of UV radiation that the film can be exposed to. In one embodiment, the UV shade and driven roll are used concomitantly to limit the UV exposure of the film entering the trigger chamber while allowing the film to be activated in an activated process. Can be done. For certain events, for example a line stop at a point downstream of the trigger chamber, the UV shade is directed to move to a closed position to prevent further activation of the membrane entering the trigger chamber. Can be done. In one embodiment, the speed at which the UV shade moves to the closed position can be close to the speed at which the membrane travels through the trigger chamber. As a result, the UV shade prevents the inert film entering the trigger chamber from being exposed to UV light, and the activated process film can continue to receive sufficient UV dose to activate the film. Can be directed to move to the closed position. As the membrane is activated, the driven roll can continue to drive the membrane forward out of the trigger chamber. In some embodiments, the driven roll can stop the forward movement of the membrane when the UV shade is moved to the closed position and almost all of the active membrane has exited the chamber. Thus, the UV shade allows the active film to be driven out of the trigger chamber and prevents further activation of the inactive film without requiring the UV lamp to be turned off. Can be used to

  In some embodiments, the active membrane exiting the trigger chamber can be temporarily stored in an inventory system. In some embodiments, the operation of the UV shade and driven roll can be operatively controlled by a control unit that is automated to control the activation of the film. The control unit can also be operatively connected to the inventory system so that the inventory section can pick up the active membrane exiting the trigger chamber.

  Trigger systems include smoked and processed meats such as sliced turkey, ham, pepperoni, and bologna, vegetable products such as tomato-based products, other food products such as jams and jellies, baby food, and electronic components Can be used in a wide range of oxygen sensitive product packaging, including limited life optical storage media, other products such as pharmaceuticals, and the like. The trigger chamber is easily adaptable to various vertical form fill and seal (VFFS) and horizontal form fill and seal (HFFS) packaging lines.

  The present invention can be used to trigger a wide range of oxygen scavenging compositions. Suitable oxygen scavenging compositions are disclosed in U.S. Pat. Nos. 5,211,875, 5,350,622, 5,498,364, and 5,399,289 to Speer et al. And WO 95/04776 and WO 95/02616, to Ching et al. Further described in WO 99/48963 to Cai et al., All of which are fully incorporated herein by reference. The oxygen scavenging composition used in the present invention can include an oxidizable organic composition that can be combined with a transition metal catalyst, eg, as disclosed in US Pat. No. 5,211,875. The oxygen scavenging composition includes, but is not limited to, an oxidizable organic composition of a substituted or unsubstituted ethylenically unsaturated hydrocarbon polymer. Conventional polymers useful in the present invention can have a molecular weight of at least 1000. Particularly useful organic compositions include, but are not limited to, styrene / butadiene copolymers, styrene / isoprene copolymers, polybutadiene, polyisoprene, ethylene / methyl acrylate / cyclohexane methyl acrylate, and mixtures thereof. The transition metal catalyst of oxygen scavenging composition is usually a transition metal salt of cobalt, manganese, nickel, iron, copper, rhodium, ruthenium, or a mixture thereof.

  Additional oxygen scavenging compositions that can be used in the present invention are described in US Pat. No. 5,958,254 to Rooney, US Pat. No. 5,859,145 to Ching et al., US Pat. No. 6,255,248 to Bansleben et al., Gauthier et al. U.S. Patent No. 6,214,254, U.S. Patent Application No. 10 / 746,626 filed December 24, 2003, and PCT Patent Application WO 99/48963, all of which are fully incorporated herein by reference. Yes. Other oxygen scavengers that can be used in connection with the present invention are disclosed in US Pat. No. 5,958,254 to Rooney, which is fully incorporated herein by reference. These oxygen scavengers comprise at least one reducible organic composition that is reduced under certain conditions, the reduced form of the composition being oxidizable by molecular oxygen, and reduction and / or subsequent oxidation of the organic composition. Is carried out independently of the presence of the transition metal catalyst. The reducible organic composition is preferably a quinone, a photoreducible dye, or a carbonyl composition having absorption in the UV spectrum.

  The oxygen scavenging composition can also contain additives such as photoinitiators, diluents, and fillers, pigments, dyes, antioxidants, stabilizers, processing aids, plasticizers, flame retardants, antifoggants, etc. .

The amount of exposure required to trigger the oxygen scavenging composition depends on several variables, such as the temperature of the film during and after the trigger, film prescription, lamp intensity, film path length, proximity to the UV source, etc. Depending on. Typically, the oxygen scavenging composition is triggered by exposure to UV-C light at the desired wavelength, intensity, and residence time to provide the composition with a dose of UV-C light of at least about 50 mJ / cm ^2. Can be done. For example, the composition, such as 1000 mJ / cm ² from 300 mJ / cm ^2, can receive a radiation dose greater than 150 mJ / cm ^2. In some cases, the UV dose can be as high as 1600 mJ / cm ² .

As described above, the present invention includes a dose management system that can be used to control the UV exposure received by a particular oxygen scavenging composition. For example, when the triggered article is used in a package with headspace, such as a modified atmospheric package (MAP), a faster oxygen collection rate is preferred, preferably with a very short induction period. In such packages, the preferred dose of UV-C light, such as between 400 mJ / cm ² and 800 mJ / cm ^2, is between 300 mJ / cm ² and 1600 mJ / cm ^2. The induction period refers to the period of time before the collection composition exhibits useful collection characteristics. Compositions that exhibit long induction times are usually retained in the inventory by the end user for a sufficient period of time before use. On the other hand, oxygen scavenging compositions with shorter induction periods are usually used within a relatively short time period so that the oxygen scavenging properties of the material are not prematurely consumed.

When an oxygen scavenging film is used in active oxygen barrier packaging, the scavenging film provides a function to help prevent oxygen from flowing through the package layer. For active barrier applications, lower oxygen scavenging rates are acceptable and preferred so that the oxygen scavenging film improves the oxygen barrier properties of the package for longer time periods. Exemplary active oxygen barrier membranes that can be used in connection with the present invention are described in PCT patent application WO 02/18489 and US Pat. No. 6,599,598 to Kuraray, both fully incorporated by reference. It is incorporated in the description. The active oxygen barrier film can include one or more layers that provide a physical oxygen barrier and one or more layers that provide an oxygen scavenging barrier (scavenger). In some cases, the active oxygen barrier layer can include a diluent polymer that similarly provides a substantially physical oxygen barrier. In some embodiments, the oxygen scavenging formulation can be physically mixed with the oxygen barrier layer. For use with barrier packages, which are specifically high-barrier long-term holding packages, the preferred dose that triggers UV-C light is between 50 mJ / cm ² and 800 mJ / cm ² .

  From the above discussion, it is apparent that the present invention provides a method, apparatus, and system that uses an apparatus that can be used to trigger an oxygen scavenging composition faster than previously achievable. It should be. The present invention also provides a trigger unit that can be used to control UV exposure.

  Those skilled in the art to which the present invention has the benefit of the teachings presented in the foregoing description and the associated drawings will contemplate many modifications and other embodiments of the invention described herein. . Accordingly, it is to be understood that the invention is not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the claims. Although specific terms have been used herein, they are general and used for descriptive purposes only and are not intended to be limiting.

1 is a cross-sectional side view of a system for activating an oxygen scavenging system including a UV shade that can be disposed between a membrane and a UV light source. FIG. FIG. 2 is a perspective view of a UV shade that can be placed between the membrane, the plurality of UV lamps, and the shade drive device. FIG. 6 is a perspective view of a cassette configured to hold a plurality of UV lamps and having a UV shade in a partially open position. FIG. 4 is a perspective view of the cassette of FIG. 3 with the cassette panel removed. FIG. 3 is a perspective view of an air circulation system that can be used to introduce conditioned air across a membrane and is removed to allow a portion of the UV chamber to be seen. FIG. 6 is a cross-sectional side perspective view of the air circulation system of FIG. 5 showing conditioned air being introduced across the membrane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 System for activating oxygen scavenging composition 12 UV chamber 14 UV light source 16 Inventory section 18 Packaging system 20 Roll 22 Membrane 24 UV lamp 26 Interior space 28 Light bank 30, 76 Inlet 32, 78 Outlet 34 Driven roll 36 Guide Roll 38 UV Shade 40 First Side 41 Second Side 42 Leading Edge 44 Endless Belt 50 Motor 52 Drive Shaft 54 Idler Roll 60 UV Cassette 62 Cassette Housing 64 First Panel 66 Second Panel 68 Opening 70 Window Pain 72, 74 Edge 80 Air circulation system 82 Air intake 86 Plenum

Claims (30)

An apparatus for activating a web having an oxygen scavenging composition,
A UV light source including a plurality of UV lamps arranged in a series and arranged in a UV chamber, the series of UV lamps having a first side and a second side through which UV light can be transmitted; The device further
A series of guide rolls disposed in the UV chamber, defining a web path around the UV light source proximate to the first side and the second side, and directing the web proximate to the UV light source;
A UV shade disposed between the UV light source and the web path, wherein the UV shade includes an end and can at least partially shield the web from exposure to UV light from the UV light source. The UV shade wraps around the first and second sides of the series of UV lamps and adjusts the degree to which the UV shade is open so as to control the UV light exposure to which the web is exposed. And an apparatus configured to be movable relative to the UV chamber between an open position, a partially open position, and a closed position.   The apparatus of claim 1, further comprising a shade drive system operable to move the UV shade from an open position to a closed position along a path that is substantially parallel to the web path. The UV shade includes an end and the shade drive system is operable to move the UV shade, the speed of the movement being approximately the rate at which the web is traveling through the UV chamber. The apparatus of claim 2.   The apparatus of claim 1, wherein when the UV shade is in the closed position, UV light is substantially prevented from contacting a web disposed in the UV chamber.   The UV light source comprises a plurality of UV lamps arranged in a bank and arranged in a UV chamber, the bank of UV lamps having a first side and a second side through which UV light can be transmitted. The apparatus according to 1.   The UV shade is retractable and extendable and is configured and arranged to wrap around the first and second sides of the bank of UV lamps, and the UV shade adjusts the degree to which the UV shade is open 6. The apparatus of claim 5, wherein the apparatus is configured to move between an open position, a partially open position, and a closed position such that a dose of light to which the web is exposed is controlled.   6. An apparatus according to claim 5, comprising two or more banks of UV lamps.   The apparatus of claim 6, wherein the UV shade is configured to move from an open position to a closed position along a path substantially parallel to the web path.   The apparatus of claim 1, wherein the UV shade is in mechanical communication with a shade drive device operable to move the UV shade between different degrees of opening. The UV shade includes an end and the shade drive system is operable to move the UV shade, the speed of the movement being approximately the rate at which the web is traveling through the UV chamber. The apparatus according to claim 9.   A bank of UV lamps is disposed in the cassette, the cassette includes a first panel and a second panel between which the bank of UV lamps is disposed, wherein the first panel and the second panel are respectively UV. 6. The apparatus of claim 5, comprising an aperture through which light can be transmitted.   The apparatus of claim 11, wherein the cassette includes opposed open side edges through which air can circulate across the surface of the UV lamp disposed therein. A fan for removing air from inside the cassette;
A heat exchanger for conditioning the air removed from the cassette;
The apparatus of claim 12, further comprising a light conditioning system having a plenum for passing conditioned air in contact with the UV lamp.   The shade drive device includes at least one endless belt wrapped around the first side and the second side and connected to the UV shade, wherein the endless belt has an open position, a closed position, and an open position and a closed position. The apparatus of claim 9, wherein the apparatus is configured to move the UV shade between any positions in between. A fan for removing air from the UV chamber;
A heat exchanger for conditioning the air removed from the UV chamber;
6. The apparatus of claim 5, further comprising an air circulation system having a plenum for passing conditioned air over the web as the web moves through the UV chamber. A system for activating a membrane having an oxygen scavenging composition comprising:
A roll of inert film having an oxygen scavenging composition in an inert state;
A UV chamber for activating the film,
The UV chamber is
An entrance through which an inert film enters the UV chamber;
A plurality of UV lamps configured in series and arranged in a UV chamber, the series of UV lamps having a first side and a second side through which UV light can be transmitted; ,
The oxygen scavenging composition is positioned in the UV chamber so that it is activated by exposure to UV light and directs the membrane in proximity to the first and second sides of the series of UV lamps. A plurality of guide rolls defining a membrane path for
It can be wrapped around the first and second sides, by adjusting the degree to which the UV shade is open, is configured to control the irradiation amount of UV light which the film is exposed, and an end A movable UV shade having a portion ;
A shade drive system operable to move the UV shade between different degrees of openness;
An exit through which the active film can exit the UV chamber;
The system for activating a membrane having an oxygen scavenging composition further comprises:
A drive roll for driving the film along the film path through the UV chamber;
The film is exposed by being operatively connected to the shade drive system and the drive roll and by adjusting the degree to which the UV shade is open and by adjusting the speed of the film as it travels through the UV chamber. And a control unit configured to command the movement of the UV shade such that the amount of UV light irradiation is controlled.   The system of claim 16, wherein the control unit is operable to move the UV shade, the speed of the movement being approximately the rate at which the film travels through the UV chamber.   The system of claim 16, wherein the control unit is configured to move the UV shade to the closed position when the forward movement of the membrane is stopped.   The system of claim 16, further comprising an inventory system for storing the active membrane, the inventory system having an inventory shuttle that can move between a high capacity state and a low capacity state. An inventory system is operatively connected to the control unit, and the control unit is responsive to the interruption of the packaging operation using the active membrane, at least one of the following:
Stopping the introduction of the inert film into the UV chamber;
Instructing the UV shade to move to the closed position;
The system of claim 19, wherein the system is configured to perform at least one of instructing an inventory system to capture and store any active film disposed in the UV chamber.   21. The system of claim 20, wherein the UV lamp shade is moved to a closed position at approximately the same time as almost all active film exits the UV chamber.   The UV shade is configured to move from the open position to the closed position in a path that is substantially parallel to the film path around the first side and the second side of the bank of UV lamps, and the UV shade is in the closed position. The system of claim 16, wherein the rate moved is approximately the speed at which the film is traveling through the UV chamber. A method for controlling the amount of UV radiation to which a film having an oxygen scavenging composition is exposed, comprising:
Providing a membrane having an inert oxygen scavenging composition;
Passing the film into a UV chamber, the UV chamber comprising a UV light source and a movable UV shade that can be at least partially disposed between the UV light source and the film. Passing it through,
Exposing the film to a UV light source for a sufficient amount of time to activate the oxygen scavenger;
Controlling the amount of UV light exposure to which the film is exposed by adjusting the degree to which the UV shade is placed between the UV light source and the film;
Supplying an active film to the packaging system ;
Moving the UV shade to a closed position in response to a stopping operation of the packaging system, wherein the UV shade moves to the closed position at a rate at which the film is approximately advanced .   24. The method of claim 23, further comprising adjusting the rate at which the film is traveling, thereby controlling the dose of UV light to which the film is exposed.   The UV shade further includes moving the UV shade to a closed position in response to stopping the operation of the packaging system so as to substantially prevent UV light from the UV light source from contacting the inert film. Item 24. The method according to Item 23.   26. The method of claim 25, further comprising adjusting a rate at which the UV shade is moved to the closed position so that the film is approximately at a traveling speed.   24. The method of claim 23, further comprising moving the UV shade to a closed position in response to stopping the advancement of the film. Detecting a stop of advancement of the film at a point downstream of the UV chamber;
Moving the UV shade such that UV light is positioned between the inert film entering the UV chamber and the UV light source such that UV light is substantially prevented from activating the inert film;
Driving the active film, and the film in the process to be activated, outside the UV chamber and to an inventory system;
Moving the U V shade to the closed position at a rate of approximately the rate that the film is traveling so that the activated process film is activated before exiting the UV chamber;
Placing the UV shade in a substantially closed position;
24. The method of claim 23, further comprising the step of stopping the advancement of the film in the UV chamber when substantially all of the active film has exited the UV chamber.   The apparatus of claim 1, wherein a roll is disposed in a UV chamber and a UV shade is configured and disposed to be wrapped around the roll.   The system of claim 16, wherein a roll is placed in a UV chamber and a UV shade is configured and arranged to wrap around the roll.

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